Synthesis, characterization, molecular docking and in vitro antibacterial assessments of anthracene-bis(hydrazine)thiosemicarbazide complexes with Co(II), Ni(II) and Cu(II) ions

As it is essential to develop novel drug candidates that have potent antibacterial as well as antioxidant activities, a new thiosemicarbazide viz N,N'-(2,2 '-((9,10,11,12)-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarbonyl)bis (hydrazine-1-carbonothioyl))dibenzamide (H6EDTS) (1) and its Co(II) (2), Ni(II) (3) and Cu(II) (4) complexes have been isolated. The tile compounds were characterized by elemental analyses and spectroscopic measurements. The compounds (2) and (4) were found to be binuclear while compound 4 was a mononuclear one. Spectral FTIR and electronic data showed that H6EDTS coordinating to metal ion as dibasic N2S2O2, NSO and N2O2 chelate in an octahedral arrangement around cobalt(II) ion and square planar one around Ni(II) and Cu(II) ions. The geometry of Cu(II) complex was further proved by its EPR spectrum which showed an intense and broad signal. The TG analyses confirmed the nature of solvent molecules and the thermal stability on complexation. Mulliken and molecular electrostatic potential (MEP) analyses utilized DFT method for the molecular design, optoelectronic properties, HOMO-LUMO energy gaps and, determination of charge density distribution and site of chemical reactivity of the molecule. In addition, all compounds were screened for in vitro antibacterial activity against four pathogenic bacteria and in addition, molecular docking simulations were performed to confirm the interaction. In addition, biological activity is extended to study DNA cleavage, and antioxidant activity viz. Superoxide radicals, and hydroxyl radicals scavenging activities. Furthermore, all compounds and reference drugs (ampicillin) were docked to the target protein using the glide dock XP protocol without performing post-docking minimization.